At least 81 Christians attending Sunday worship service in their historic church were killed and 131 others were wounded after two Taliban suicide bombers stormed the building in northwest Pakistan. The victims of what is being called the deadliest-ever attack on Christians include 37 women.

Blood, body parts and pages from the Bible could be seen at the church after the attack, Pakistan's Dawn newspaper said, calling it "the deadliest ever (attack) targeting Christians in Pakistan."

About 400 worshippers were exchanging greetings after the service at the 130-year-old All Saints Church in the city of Peshawar when the two bombers, each carrying about 6kg (13 pounds) of explosives, launched the attack. The walls were pockmarked with ball bearings that had been packed into the bombs to cause maximum carnage in the busy church, the newspaper said.

"I saw myself in the air and then on the ground inside a huge fire of ball," Sabir John, a church member who lost one of his arms in the blast, told The Guardian.

There are about 70,000 Christians in Peshawar. The community accounts for about two percent of the 180 million people in Pakistan.

Sections of the country's Christians reacted with anger. Protest marches were held across Pakistan to demand protection. Christians are also routinely targeted by Islamist extremists with accusations under the country's notorious anti-blasphemy laws.

The bombers were between the ages of 20 and 22, according to reports.

Speaking to Reuters, a faction of the Tehrik-i-Taliban Pakistan (TTP) claimed responsibility for the attack, saying, "(The Christians) are the enemies of Islam, therefore we target them. We will continue our attacks on non-Muslims on Pakistani land."

The TTP faction, created to kill foreigners to avenge U.S. drone strikes on Taliban and al Qaeda operatives, told Agence France Presse, "We carried out the suicide bombings at Peshawar church and will continue to strike foreigners and non-Muslims until drone attacks stop."

Muslim minorities, including Shias and Ahmaddiyas, also often face attacks by Sunni terror groups in Pakistan.

Peshawar is near the tribal areas that are strongholds of the Pakistani Taliban. People in Pakistan say civilians also get killed in drone attacks. On Sunday, a drone strike killed six militants and wounded four in Pakistan's tribal area of South Waziristan.

"These drone strikes have a negative impact on the mutual desire of both countries to forge a cordial and cooperative relationship and to ensure peace and stability in the region," Pakistan's Ministry of Foreign Affairs said in a statement.

Pakistani Prime Minister Nawaz Sharif, who had proposed peace talks with the TTP earlier this month, called the attack "cruel," and said it is against the tenets of Islam.

"Terrorists have no religion and targeting innocent people is against the teachings of Islam and all religions," Sharif said in a statement. "Cruel acts of terrorism reflect the brutality and inhumane mindset of the terrorists."

The Pakistani government has announced three days of mourning were announced, and formed a four-member committee to gather evidence based on accounts of witnesses.

Political parties agreed to hold peace-talks with the Taliban earlier this month.

However, Imran Khan, who heads the regional ruling party, sought to highlight the futility of the federal government's peace efforts with the Taliban. "Isn't it strange that whenever peace talks are pursued, these attacks take place, and I want to point out that there was also a drone strike today," he told reporters.